Conventionally, there is known a technique to generate a synthesized image in an expanded dynamic range by shooting the same subject while changing exposure settings and synthesizing a plurality of obtained images (for example, Patent Document 1).
As a technique to detect a positional shift of pictorial pattern between images output from different imaging devices with different resolutions, the following Patent Document 2 is well known. In this prior art, first wide-area search is performed between a high-resolution image and a low-resolution image to find a candidate for a matching region. Next, in the range of the matching region, both images are subjected to pixel interpolation and a region in which the pictorial pattern matches to the detail is found by the comparison between interpolated pixels.    Patent Document 1: Japanese Unexamined Patent Application Publication No. 2002-305684    Patent Document 2: International Publication WO95/04329 Pamphlet